1. Field of the Invention
This invention relates to monolithic microwave integrated circuits, and, more particularly, to a method of fabricating such circuits.
2. Description of the Prior Art
Prior art attempts to manufacture monolithic microwave integrated circuits have met with limited success due to the high electrical loss, high interelemental parasitic capacitances, which leads to inadequate isolation of elements, and high conductor-to-substrate capacitances associated with bulk silicon.
U.S. patent application Ser. No. 109,174, discloses one successful technique for the production of active devices using silicon-on-sapphire material. The silicon layer overlying the sapphire is etched to form islands, and active devices are formed within the islands. Metallization layers for contacts and electrical interconnections are then applied.